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rail transport l engineering

EQUIPMENT FOR THE RAILWAY INDUSTRY

ŽĎAS, a company based in Žďár nad Sázavou,

manufactures high-quality and reliable devices for

applications in the railway industry supported by cutting

edge technology and significant references. The company

mainly designs lines for the production of railway wheels

and axles, and presses designed for the assembly

and disassembly of railway wheelsets, always

to individual customer requirements.

ŽĎAS offers a complete line for forming

railway wheels, which consists of a heating rotary hearth furnace, four hydraulic

presses with unit drives, one rolling mill,

handling equipment, marking equipment,

and equipment for measuring the dimensions of the semi-finished wheels. Furthermore, the line is equipped with automatic

tool change in hydraulic presses, including the preheating of tools. At the beginning of the production process, the cut input material blank is placed into a rotary

hearth furnace. After heating, a manipulator places the material in the descaling device. When the scale has been removed,

the manipulator moves the heated block

to the CKZW 5600 upsetting press, where the block is centred into the press axis

by means of a centring device. In the

press, the block is compressed into the

shape of a disk and another manipulator

transfers it to the CKVZ 8000 forming

press, where the centring and forming

operation takes place. This is followed by

the operation of punching the formed semi-product in the CKVD 1000 punching

press. Then the final shape of the wheel is

rolled in a rolling mill. In the CKVP 4000

dishing press, the wheel plate is then sized

and dished. The finished wheel is marked

in the stamping press and its shape is measured to see if it corresponds to specifications. The company is also able to provide the equipment with remote

management, diagnostics, and data collection, which will provide input information for predictive maintenance and integration with Industry 4.0.

The axles are forged from vacuum steel

billets of the required quality. After being

heated to forming temperature, the basic

shape of the axle is forged on an integrated forging unit which consists of a CKNV

1000 push-down forging press, a QKK 1.5

forging manipulator, and a rotary lifting

table. The basic axle design is generally

forged using three die sizes, which allows

for forging within the required specifications of ±1.5 mm, with a high degree of for-

puter controlled heat treatment to achieve optimal mechanical properties. The deflection and shape deformation caused by

the heat treatment is then adjusted on an

RL 400 straightening press.

Railway bogie wheels must have different properties in different places of their

surface; they must be flexible and hard at

the same time. The required hardness

is achieved by reducing the elasticity, and

therefore only the area of the wheel that

rolls along the track is hardened. The

CDRA hydraulic press is used for assembling railway wheelsets and cold pressing.

The device also enables the pressing of

components between the wheels and the

pressing and inspection of the pressed joints. The press cylinder located in the fixed

crossbeam uses a selected force over the

pressed parts against the support crossbeam. The hydraulic wheel centring device

is located on this, and the hydraulic axle

centring device is located on the rear

crossbeam. The control system provides

press control and operation and fault diagnostics. The CDRM press is designed for

cold pressing and the pressing of railway

Railway bogie wheelsets assembled using the CDRA/CDRM hydraulic presses

ging action. High mechanical properties

of the axles are also achieved thanks to

forged depth in the diameter transitions.

After forging, the axle undergoes a com-

Axle straightening on the RL 400 hydraulic straightening press

wheelsets together. The device enables

the assembly and disassembly of wheelsets for locomotives and railway cars with

simultaneous recording of pressing force

characteristics depending on the length

of the pressed joint. After the pressing

is complete, a report for archiving the

complete process is printed. The press cylinder rests on a support beam which travels on wheels on two beams. Depending

on the type of wheelset, the pressing force is absorbed by a support beam in predetermined locked positions. The advantages of both devices include precise

control of the pressing force, simple operation, and high performance.

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special 2020

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